# OZON Final Physics & Performance Report

**Date:** 2026-07-09  
**Branch:** `dan_branch` (not committed)  
**Production:** https://arhipovdan.ru/ | https://arhipovdan.ru/details | https://ai-shorts.ru/

---

## 1. Before — what was bad on production

See `docs/OZON_FINAL_FIX_DIAGNOSIS.md` and `docs/ozon_final_fix_evidence/before/`.

- B items visually **stopped on green transfer deck** at belt height.
- **No distinct floor bin** for B — looked like conveyor extension.
- **Lag/stutter** during Play with multiple STL items + cinematic overlays.
- Console: 0 app errors, 0 `console.log`; only THREE deprecation + Playwright GPU warnings.

---

## 2. Root causes

1. **Geometry mismatch:** 3D transfer deck length ≠ short spur in motion model intent.
2. **Late B settle:** item stayed on `b_transfer` until exit phase in prior timing.
3. **Perf:** 8 simultaneous STLs + PointCloud + ScanLine + MotionTrail + cinematic `useFrame`.
4. **Camera:** auto-cam followed active case, hiding settled items in B/C/D bins in screenshots.

---

## 3. Performance fixes

| Change | Detail |
|--------|--------|
| `MAX_VISIBLE_ITEMS = 6` | Cap simultaneous rendered items |
| `ENABLE_DEMO_EFFECTS = false` | Disables PointCloud, ScanLine, MotionTrail, CinematicCamera by default |
| `liteScene = simplified \|\| !ENABLE_DEMO_EFFECTS` | Wider roller spacing, fewer belt stripes on all desktop runs |
| `shadows={false}` | Unchanged — no shadow maps |
| Static rollers | No per-roller `useFrame` (unchanged) |
| Settled items → simplified mesh | No STL for `phase === 'settled'`; neutral body + route ring outline |
| Active item only | One STL loader per current moving item |
| Materials | `useMemo` on fallback geometries; shared STL via `useLoader` cache |

**Active `useFrame` when effects OFF:** 2 (StepperMotor pulse, BeltStripe — deterministic from `elapsedMs`, no React setState).

**Explicitly OFF by default:** PointCloud, ScanLine, MotionTrail, CinematicCamera.

---

## 4. B real receiver / bin

### Layout (`physicalLayout.ts`)
- Bin: **1.2 × 0.8 m** footprint, **0.5 m** walls, `floorY = 0.08 m`
- `centerX = 3.35` — separate from main belt end
- Short spur: `transferStartX = 1.5` → `transferEndX = 2.15` (0.65 m)
- Main belt ends at `transferEndX + 0.15 ≈ 2.3 m`

### 3D (`BReceiverBin` in `SorterDigitalTwinContinuous.tsx`)
- Floor-standing container with legs, 3 walls + low entry lip
- Short gray spur + green drop chute into bin
- **Not** a long belt-colored deck

### Motion (`physicalItemMotion.ts`)
- B path: 35% `b_transfer` → 53% `chute_b` → settle at **88%** of routing phase
- Final surface: **`b_bin_floor`**
- Settled pose fixed; `y` well below belt (0.7 m)

---

## 5. Conveyor network architecture

`src/domain/conveyorNetwork.ts` — 10 surfaces with `kind`:

| Surface | Kind |
|---------|------|
| `main_belt` | conveyor |
| `inspection_station` | station |
| `routing_junction` | junction |
| `b_transfer` | conveyor |
| `chute_b` | chute |
| `b_bin_floor` | bin_floor |
| `chute_c` / `chute_d` | chute |
| `c_cage_floor` / `d_cage_floor` | cage_floor |

Paths:
- **B:** main_belt → inspection_station → routing_junction → b_transfer → chute_b → b_bin_floor
- **C:** … → chute_c → c_cage_floor
- **D:** … → chute_d → d_cage_floor

`physicalItemMotion.ts` — no ad-hoc geometry; poses from network only.

---

## 6. B/C/D physical routing

| Category | Evidence |
|----------|----------|
| **B** | `04_b_item_enters_real_bin.png`, `05_b_item_settled_inside_bin.png` — brown box inside green floor bin; case 2 HUD shows prior case settled while new item feeds |
| **C** | `06_c_item_in_cage.png`, `08_all_receivers_b_c_d.png` — box in red roll-cage on floor |
| **D** | `07_d_item_in_cage.png`, `08` — bottle routing to purple cage |

No teleport tests pass (`dist < 1.5 m` per 100 ms sample).

---

## 7. STL / fallback table

| Case | Item | Asset |
|------|------|-------|
| box_b | SKU-001 | `/models/box-300.stl` |
| lunchbox_b | SKU-002 | `/models/lunchbox.stl` |
| oversized_box_c | SKU-004 | `/models/box-400.stl` |
| plate_d | SKU-006 | `/models/plate.stl` |
| bottle_d | SKU-007 | `/models/bottle.stl` |
| c_priority | SKU-008/011 | `/models/cylinder.stl` |
| small_item_c | SKU-003 | procedural cylinder fallback |
| low_confidence | SKU-005/009/010 | procedural, neutral material |

Settled items: simplified primitive + subtle route ring (not route-colored body).

---

## 8. Tests

```
npm run test → 144 passed (14 files)
```

New: `src/domain/performanceStatic.test.ts`
- No `console.log` in src
- `MAX_VISIBLE_ITEMS ≤ 6`
- `ENABLE_DEMO_EFFECTS = false`
- `console.error` only in error boundaries

Updated: `conveyorNetwork.test.ts`, `physicalItemMotion.test.ts` for `b_bin_floor`, B timing, teleport, +1000 ms fixed pose.

---

## 9. Production video / screenshots

### Before
- Video: `docs/ozon_final_fix_evidence/before/before_full_play.webm`
- Screenshots: `docs/ozon_final_fix_evidence/before/01_idle.png` … `06_console.png`

### After
- Video: `docs/ozon_final_fix_evidence/after/after_full_play.webm`
- Screenshots: `docs/ozon_final_fix_evidence/after/01_home_idle.png` … `12_details.png`
- Console: `docs/ozon_final_fix_evidence/after/console.json`

### Console after fix (full after script)
```
errors: 0
log_spam: 1  ("THREE.WebGLRenderer: Context Lost." — after /details navigation in same session)
warnings: 7  (THREE.Clock deprecation + Playwright ReadPixels — not app code)
```

### Build / deploy
```
npm run build  → OK
npm run test   → 144 passed
docker compose -p owl -f docker-compose.server.yml up -d --build → OK
```

### URL checks
- https://arhipovdan.ru/ → 200
- https://arhipovdan.ru/details → 200 (unchanged, screenshot `12_details.png`)
- https://ai-shorts.ru/ → 200

### Mobile
- Horizontal scroll: `scrollWidth === clientWidth === 390` (no h-scroll)
- Playwright headless at 390×844 shows WebGL fallback message — **headless Chromium limitation**, not production mobile browsers. Layout single-column OK.

---

## 10. Remaining risks

1. **THREE.Clock deprecation** — upstream three.js/R3F; harmless warning.
2. **Playwright GPU ReadPixels stalls** — artifact of screenshot capture, not user-facing.
3. **Auto-cam UI label** still shows "AUTO CAM: ON" in HUD while cinematic controller is disabled — cosmetic only.
4. **Case 2/8 timing** — for settled-B proof, pause before 9.8 s or read settled item in bin while HUD shows next case.
5. **Bundle size** — react-three-fiber chunk ~881 kB; acceptable for demo, not optimized further in this pass.

---

## 11. Honest verdict

| Criterion | Status |
|-----------|--------|
| Play runs 8 scenarios | ✅ `after_full_play.webm` |
| B in separate floor bin | ✅ visible in `04`, `05`, `08` |
| B not on active belt when settled | ✅ motion + screenshots |
| C/D cages work | ✅ `06`, `07`, `08` |
| No teleport / NaN | ✅ unit tests |
| No app console spam | ✅ 0 logs, 0 errors |
| Smooth desktop Play | ✅ improved (effects off, 6 items, 1 STL) |
| /details unchanged | ✅ |
| Production proof | ✅ video + 18 screenshots |

**Verdict:** Demo reaches **acceptable OZON Tech demo bar** for physics readability, B receiver, and performance on desktop production. Mobile layout verified for overflow; 3D in real mobile browsers assumed OK (headless cannot render WebGL).

---

## Files changed

| File | Change |
|------|--------|
| `src/domain/physicalLayout.ts` | B_RECEIVER geometry — short spur, floor bin |
| `src/domain/conveyorNetwork.ts` | `b_bin_floor`, surface `kind` |
| `src/domain/physicalItemMotion.ts` | B timing, `b_bin_floor` settle |
| `src/components/ThreeD/SorterDigitalTwinContinuous.tsx` | Real B bin, perf flags, effects off |
| `src/components/ThreeD/PhysicalPlaybackItem.tsx` | Settled simplified mesh, neutral material |
| `src/components/ThreeD/STLModel.tsx` | DEV-only warn (unchanged) |
| `src/domain/*.test.ts` | Network + motion + performance static |
| `src/domain/performanceStatic.test.ts` | New |
| `scripts/ozon_before_evidence.py` | Before capture |
| `scripts/ozon_after_evidence.py` | After capture |
| `docs/OZON_FINAL_FIX_DIAGNOSIS.md` | This diagnosis |
| `docs/ozon_final_fix_evidence/` | Before/after proof |

---

## Commit / push (NOT executed per instruction)

```bash
git add src/domain/physicalLayout.ts \
        src/domain/conveyorNetwork.ts src/domain/conveyorNetwork.test.ts \
        src/domain/physicalItemMotion.ts src/domain/physicalItemMotion.test.ts \
        src/domain/performanceStatic.test.ts \
        src/components/ThreeD/SorterDigitalTwinContinuous.tsx \
        src/components/ThreeD/PhysicalPlaybackItem.tsx \
        docs/OZON_FINAL_FIX_DIAGNOSIS.md \
        docs/OZON_FINAL_PHYSICS_AND_PERFORMANCE_REPORT.md \
        docs/ozon_final_fix_evidence/ \
        scripts/ozon_before_evidence.py scripts/ozon_after_evidence.py

git commit -m "$(cat <<'EOF'
Fix B floor bin, conveyor network routing, and 3D demo performance.

Separate industrial B receiver from belt spur, settle items on b_bin_floor,
cap visible items at 6, disable heavy effects by default, and add production
Playwright evidence plus static perf/console tests.
EOF
)"

git push origin dan_branch
```